Clamp



FIG. 1 is a front elevational view of a clamp showing my new design;

FIG. 2 is a right side elevational view therof, the left side being a mirror image thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a rear elevational view thereof; and

FIG. 5 is a bottom plan view thereof. 

The ornamental design for a clamp, as shown and described. 